Sen. Kirsten Gillibrand Kirsten Elizabeth GillibrandWoman to undecided Biden: 'Just say yes' to 2020 bid Hillary Clinton says she 'can't imagine' running for president again Kamala Harris supports decriminalizing sex work MORE (N.Y.) will join a growing list of Democratic co-sponsors of Sen. Bernie Sanders Bernard (Bernie) SandersSenate Dems seek to turn tables on GOP in climate change fight Bernie Sanders Town Hall finishes third in cable news race, draws 1.4 million viewers Woman to undecided Biden: 'Just say yes' to 2020 bid MORE's (I-Vt.) "Medicare for all" proposal, according to a Friday report from Mic.

Gillibrand joins other possible 2020 Democratic White House hopefuls in supporting the bill, including Sens. Cory Booker Cory Anthony BookerWoman to undecided Biden: 'Just say yes' to 2020 bid Poll shows Biden leads Democrats vying for 2020 nomination Why not an 'Organic' Green New Deal? MORE (N.J.), Kamala Harris Kamala Devi HarrisDem introduces bill to push back Ohio presidential primary Cohen grilled by Senate Intelligence panel Bernie Sanders Town Hall finishes third in cable news race, draws 1.4 million viewers MORE (Calif.) and Elizabeth Warren Elizabeth Ann WarrenWoman to undecided Biden: 'Just say yes' to 2020 bid Raising taxes on the wealthy is 'extremely popular,' says Dem pollster 64 percent say Democratic Party supports socialism, says poll MORE (Mass.).

Sanders will unveil the measure at an event on Wednesday. The bill is quickly gaining Democratic support, and the issue of single payer is emerging as a key test for possible presidential contenders.

ADVERTISEMENT

Gillibrand expressed some support for single-payer health care in June as well.

"Health care should be a right, it should never be a privilege. We should have Medicare for all in this country," she said, according to CNN.

Gillibrand's office did not respond to a request for comment on the Mic report.